Class: Tupelo::Client::Transaction

Inherits:
Object
  • Object
show all
Defined in:
lib/tupelo/util/boolean.rb,
lib/tupelo/client/transaction.rb

Defined Under Namespace

Classes: TransactionThread

Constant Summary collapse

STATES = 
[
  OPEN      = :open,    # initial state
  CLOSED    = :closed,  # client thread changes open -> closed
                        # after closed, client cannot touch any state
  PENDING   = :pending, # worker thread changes closed -> pending | failed
  DONE      = :done,    # worker thread changes pending -> done (terminal)
  FAILED    = :failed   # worker thread changes pending -> failed (terminal)
]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(client, deadline: nil) ⇒ Transaction

Returns a new instance of Transaction.



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# File 'lib/tupelo/client/transaction.rb', line 129

def initialize client, deadline: nil
  @client = client
  @worker = client.worker
  @log = client.log
  @deadline = deadline
  @global_tick = nil
  @exception = nil
  @local_tick = nil
  @queue = client.make_queue
  @mutex = Mutex.new
  @writes = []
  @pulses = []
  @take_templates = []
  @read_templates = []
  @take_tuples_for_remote = []
  @take_tuples_for_local = []
  @read_tuples_for_remote = []
  @read_tuples_for_local = []
  @granted_tuples = nil
  @missing = nil
  @tags = nil
  @_take_nowait = nil
  @_read_nowait = nil
  
  if deadline
    worker.at deadline do
      cancel(TimeoutError) if open?
    end
  end
  
  open!
end

Instance Attribute Details

#client ⇒ Object (readonly)

Returns the value of attribute client.



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# File 'lib/tupelo/client/transaction.rb', line 93

def client
  @client
end

#deadline ⇒ Object (readonly)

Returns the value of attribute deadline.



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# File 'lib/tupelo/client/transaction.rb', line 95

def deadline
  @deadline
end

#exception ⇒ Object (readonly)

Returns the value of attribute exception.



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# File 'lib/tupelo/client/transaction.rb', line 99

def exception
  @exception
end

#global_tick ⇒ Object (readonly)

Returns the value of attribute global_tick.



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# File 'lib/tupelo/client/transaction.rb', line 97

def global_tick
  @global_tick
end

#granted_tuples ⇒ Object (readonly)

Returns the value of attribute granted_tuples.



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# File 'lib/tupelo/client/transaction.rb', line 108

def granted_tuples
  @granted_tuples
end

#local_tick ⇒ Object (readonly)

Returns the value of attribute local_tick.



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# File 'lib/tupelo/client/transaction.rb', line 98

def local_tick
  @local_tick
end

#missing ⇒ Object (readonly)

Returns the value of attribute missing.



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# File 'lib/tupelo/client/transaction.rb', line 109

def missing
  @missing
end

#pulses ⇒ Object (readonly)

Returns the value of attribute pulses.



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# File 'lib/tupelo/client/transaction.rb', line 101

def pulses
  @pulses
end

#read_templates ⇒ Object (readonly)

Returns the value of attribute read_templates.



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# File 'lib/tupelo/client/transaction.rb', line 103

def read_templates
  @read_templates
end

#read_tuples_for_local ⇒ Object (readonly)

Returns the value of attribute read_tuples_for_local.



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# File 'lib/tupelo/client/transaction.rb', line 107

def read_tuples_for_local
  @read_tuples_for_local
end

#read_tuples_for_remote ⇒ Object (readonly)

Returns the value of attribute read_tuples_for_remote.



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# File 'lib/tupelo/client/transaction.rb', line 106

def read_tuples_for_remote
  @read_tuples_for_remote
end

#status ⇒ Object (readonly)

Returns the value of attribute status.



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# File 'lib/tupelo/client/transaction.rb', line 96

def status
  @status
end

#tags ⇒ Object (readonly)

Returns the value of attribute tags.



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# File 'lib/tupelo/client/transaction.rb', line 110

def tags
  @tags
end

#take_templates ⇒ Object (readonly)

Returns the value of attribute take_templates.



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# File 'lib/tupelo/client/transaction.rb', line 102

def take_templates
  @take_templates
end

#take_tuples_for_local ⇒ Object (readonly)

Returns the value of attribute take_tuples_for_local.



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# File 'lib/tupelo/client/transaction.rb', line 105

def take_tuples_for_local
  @take_tuples_for_local
end

#take_tuples_for_remote ⇒ Object (readonly)

Returns the value of attribute take_tuples_for_remote.



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# File 'lib/tupelo/client/transaction.rb', line 104

def take_tuples_for_remote
  @take_tuples_for_remote
end

#worker ⇒ Object (readonly)

Returns the value of attribute worker.



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# File 'lib/tupelo/client/transaction.rb', line 94

def worker
  @worker
end

#writes ⇒ Object (readonly)

Returns the value of attribute writes.



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# File 'lib/tupelo/client/transaction.rb', line 100

def writes
  @writes
end

Instance Method Details

#abort ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 291

def abort
  client.abort
end

#async(&block) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/tupelo/client/transaction.rb', line 362

def async &block
  raise ArgumentError, "must provide block" unless block
  TransactionThread.new(self) do ## Fiber?
    begin
      val =
        if block.arity == 0
          instance_eval &block
        else
          yield self
        end
      commit.wait
      val
    rescue TransactionFailure => ex
      log.info {"retrying #{t.inspect}: #{ex}"}
      retry
    rescue TransactionAbort
      log.info {"aborting #{t.inspect}"}
    end
  end
end

#cancel(err = TransactionAbort) ⇒ Object

Called by another thread to cancel a waiting transaction.



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# File 'lib/tupelo/client/transaction.rb', line 554

def cancel err = TransactionAbort
  worker_push do
    raise unless in_worker_thread?
    if not open? or @global_tick or @exception
      log.info {"cancel was applied too late: #{inspect}"}
    else
      @exception = err.new
      failed!
      @queue << false
    end
  end
  nil
end

#check_open ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 214

def check_open
  if failed?
    # checking this here is mostly a courtesy to client code; it is possible
    # (a benign race condition) for the failure flag to be set later,
    # even while a #write or #take method still has not returned.
    raise exception
  elsif not open?
    raise TransactionStateError, "not open: #{inspect}"
  end
end

#check_tuples(tuples) ⇒ Object

:section: Client methods



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# File 'lib/tupelo/client/transaction.rb', line 207

def check_tuples tuples
  tuples.each do |tuple|
    tuple.respond_to?(:size) and tuple.respond_to?(:fetch) or
      raise ArgumentError, "Not a tuple: #{tuple.inspect}"
  end
end

#client_id ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 162

def client_id
  client.client_id
end

#commit ⇒ Object

idempotent



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# File 'lib/tupelo/client/transaction.rb', line 305

def commit
  if open?
    if @writes.empty? and @pulses.empty? and
       @take_tuples_for_remote.all? {|t| t.nil?} and
       @read_tuples_for_remote.all? {|t| t.nil?}
      @global_tick = worker.global_tick ## ok?
      done!
      log.info {"not committing empty transaction"}
    else
      closed!
      log.info {"committing #{inspect}"}
      worker_push self
    end
  else
    raise exception if failed?
  end
  return self
end

#done(global_tick, granted_tuples) ⇒ Object

Raises:



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# File 'lib/tupelo/client/transaction.rb', line 522

def done global_tick, granted_tuples
  raise TransactionStateError, "must be pending" unless pending?
  raise unless in_worker_thread?
  raise if @global_tick or @exception

  @global_tick = global_tick
  done!
  @granted_tuples = granted_tuples
  log.info {"done with #{inspect}"}
  @queue << true
end

#error(ex) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 544

def error ex
  raise unless in_worker_thread?
  raise if @global_tick or @exception
  
  @exception = ex
  failed!
  @queue << false
end

#fail(missing) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 534

def fail missing
  raise unless in_worker_thread?
  raise if @global_tick or @exception
  
  @missing = missing
  @exception = TransactionFailure
  failed!
  @queue << false
end

#fail! ⇒ Object

Client may call this before commit. In transaction do…end block, this causes transaction to be re-executed.

Raises:



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# File 'lib/tupelo/client/transaction.rb', line 297

def fail!
  raise if in_worker_thread?
  raise unless open?
  failed!
  raise TransactionFailure
end

#in_worker_thread? ⇒ Boolean

:section: Worker methods

Returns:

  • (Boolean) 


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# File 'lib/tupelo/client/transaction.rb', line 385

def in_worker_thread?
  worker.in_thread?
end

#inspect ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 178

def inspect
  stat_extra =
    case
    when pending?
      "at local_tick: #{local_tick}"
    when done?
      "at global_tick: #{global_tick}"
    end
  
  stat = [status, stat_extra].compact.join(" ")
  
  ops = [ ["write", writes], ["pulse", pulses],
        ["take", take_templates], ["read", read_templates] ]
        ## exclude templates that were satisfied locally by writes
  ops.map! do |label, tuples|
    ["#{label} #{tuples.map(&:inspect).join(", ")}"] unless tuples.empty?
  end
  ops.compact!
  ops << "missing: #{missing}" if missing

  ## show take/read tuples too?
  ## show current tick, if open or closed
  ## show nowait
  
  "<#{self.class} #{stat} #{ops.join('; ')}>"
end

#log(*args) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 170

def log *args
  if args.empty?
    @log
  else
    @log.unknown *args
  end
end

#or(*templates) ⇒ Object Also known as: match_any 



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# File 'lib/tupelo/util/boolean.rb', line 21

def or *templates
  client.or *templates
end

#prepare(new_tuple = nil) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 389

def prepare new_tuple = nil
  return false if closed? or failed? # might change during this method
  raise unless in_worker_thread?

  if new_tuple
    return true if take_tuples_for_local.all? and read_tuples_for_local.all?

    take_tuples_for_local.each_with_index do |tuple, i|
      if not tuple and take_templates[i] === new_tuple
        take_tuples_for_local[i] = new_tuple
        take_tuples_for_remote[i] = new_tuple
        log.debug {"prepared #{inspect} with #{new_tuple}"}
        break
      end
    end

    read_tuples_for_local.each_with_index do |tuple, i|
      if not tuple and read_templates[i] === new_tuple
        read_tuples_for_local[i] = new_tuple
        read_tuples_for_remote[i] = new_tuple
        log.debug {"prepared #{inspect} with #{new_tuple}"}
      end
    end

  else
    ## optimization: use tuple cache
    skip = nil
    (take_tuples_for_local.size...take_templates.size).each do |i|
      template = take_templates[i]
      
      if wt = @writes.find {|tuple| template === tuple}
        take_tuples_for_remote[i] = nil
        take_tuples_for_local[i] = wt.dup
        @writes.delete wt
        next
      end

      take_tuples_for_local[i] = take_tuples_for_remote[i] =
        worker.tuplespace.find_match_for(template,
          distinct_from: take_tuples_for_local)
      
      if take_tuples_for_local[i]
        log.debug {"prepared #{inspect} with #{take_tuples_for_local[i]}"}
      else
        if @_take_nowait and @_take_nowait[i]
          (skip ||= []) << i
        end
      end
    end

    skip and skip.reverse_each do |i|
      take_tuples_for_local.delete_at i
      take_tuples_for_remote.delete_at i
      take_templates.delete_at i
      @_take_nowait.delete i
    end
    
    skip = nil
    (read_tuples_for_local.size...read_templates.size).each do |i|
      template = read_templates[i]

      if wt = @writes.find {|tuple| template === tuple}
        read_tuples_for_remote[i] = nil
        read_tuples_for_local[i] = wt.dup
        next
      end

      read_tuples_for_local[i] = read_tuples_for_remote[i] =
        worker.tuplespace.find_match_for(template,
          distinct_from: take_tuples_for_local)
      
      if read_tuples_for_local[i]
        log.debug {"prepared #{inspect} with #{read_tuples_for_local[i]}"}
      else
        if @_read_nowait and @_read_nowait[i]
          (skip ||= []) << i
        end
      end
    end

    skip and skip.reverse_each do |i|
      read_tuples_for_local.delete_at i
      read_tuples_for_remote.delete_at i
      read_templates.delete_at i
      @_read_nowait.delete i
    end
  end
  
  ## convert cancelling write/take to pulse
  ## convert cancelling take/write to read
  
  if take_tuples_for_local.all? and read_tuples_for_local.all?
    @queue << true
    log.debug {
      "prepared #{inspect}, " +
      "take tuples: #{take_tuples_for_local}, " +
      "read tuples: #{read_tuples_for_local}"}
  end
  
  return true
end

#pulse(*tuples) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 235

def pulse *tuples
  check_open
  check_tuples tuples
  blobber = worker.blobber
  @pulses.concat tuples.map {|t| blobber.load(blobber.dump(t))}
  nil
end

#read(template_spec) ⇒ Object

transaction applies only if template has a match



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# File 'lib/tupelo/client/transaction.rb', line 268

def read template_spec
  check_open
  template = worker.make_template(template_spec)
  @read_templates << template
  log.debug {"asking worker to read #{template_spec.inspect}"}
  worker_push self
  wait
  return read_tuples_for_local.last
end

#read_nowait(template_spec) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 278

def read_nowait template_spec
  check_open
  template = worker.make_template(template_spec)
  @_read_nowait ||= {}
  i = @read_templates.size
  @_read_nowait[i] = true
  @read_templates << template
  log.debug {"asking worker to read #{template_spec.inspect}"}
  worker_push self
  wait
  return read_tuples_for_local[i]
end

#submit ⇒ Object

Raises:



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# File 'lib/tupelo/client/transaction.rb', line 514

def submit
  raise TransactionStateError, "must be closed" unless closed?
  raise unless in_worker_thread?

  @local_tick = worker.send_transaction self
  pending!
end

#subspace(tag) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 166

def subspace tag
  client.subspace tag
end

#take(template_spec) ⇒ Object

raises TransactionFailure



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# File 'lib/tupelo/client/transaction.rb', line 244

def take template_spec
  check_open
  template = worker.make_template(template_spec)
  @take_templates << template
  log.debug {"asking worker to take #{template_spec.inspect}"}
  worker_push self
  wait
  return take_tuples_for_local.last
end

#take_nowait(template_spec) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 254

def take_nowait template_spec
  check_open
  template = worker.make_template(template_spec)
  @_take_nowait ||= {}
  i = @take_templates.size
  @_take_nowait[i] = true
  @take_templates << template
  log.debug {"asking worker to take_nowait #{template_spec.inspect}"}
  worker_push self
  wait
  return take_tuples_for_local[i]
end

#unprepare(missing_tuple) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 491

def unprepare missing_tuple
  return false if closed? or failed? # might change during this method
  raise unless in_worker_thread?

  @take_tuples_for_remote.each do |tuple|
    if tuple == missing_tuple ## might be false positive, but ok
      fail [missing_tuple]
        ## optimization: manage tuple cache
      return false
    end
  end

  @read_tuples_for_remote.each do |tuple|
    if tuple == missing_tuple ## might be false positive, but ok
      fail [missing_tuple]
      return false
    end
  end

  ## redo the conversions etc
  return true
end

#value ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 347

def value
  wait
  granted_tuples
end

#wait ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 328

def wait
  return self if done?
  raise exception if failed?
  
  log.debug {"waiting for #{inspect}"}
  @queue.pop
  log.debug {"finished waiting for #{inspect}"}

  return self if done? or open?
  raise exception if failed?
  log.error inspect
  raise "bug: #{inspect}"

rescue TransactionAbort, Interrupt, TimeoutError => ex ## others?
  worker_push Unwaiter.new(self)
  cstr = "client #{client_id} (#{log.progname})"
  raise ex.class, "#{ex.message}: #{cstr} waiting for #{inspect}"
end

#worker_push(event = Proc.new) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 324

def worker_push event=Proc.new
  worker << event
end

#write(*tuples) ⇒ Object 



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# File 'lib/tupelo/client/transaction.rb', line 225

def write *tuples
  check_open
  check_tuples tuples
  blobber = worker.blobber
  @writes.concat tuples.map {|t| blobber.load(blobber.dump(t))}
    # this is both to de-alias (esp. in case of marshal or yaml) and
    # to convert symbols to strings (in case of msgpack or json)
  nil
end